Nonwoven Joint Tape Having Low Moisture Expansion Properties and Method for Using Same

ABSTRACT

The invention is directed to a joint tape for finishing a joint between boards comprising a nonwoven substrate that does not swell substantially in the presence of water. The invention further provides a method of finishing a joint between boards comprising (i) applying a joint tape of the invention to a joint between boards by embedding the joint tape in a first coat of joint compound, (ii) applying a second coat of joint compound over the tape, wherein step (ii) is carried out before the joint tape and joint compound applied in step (i) have substantially dried, and optionally (iii) applying a third fill or finish coat of joint compound over the tape, wherein step (iii) is carried out before the joint tape and second coat have substantially dried.

BACKGROUND OF THE INVENTION

Walls, ceilings, floors, partitions, bathtub surround and the like arecommonly constructed from multiple pieces of board (sometimes referredto as “panels”). The board may be composed of any of a variety ofmaterials, including but not limited to, cementitious materials such as,for example, cement or gypsum. Typically, when two pieces of board abuteach other in use, a gap or seam referred to as a joint is definedbetween boards. It is well known to fill and coat the joints with aspecially prepared adhesive called “joint compound.” Two types of jointcompound are known in the art: a setting type and drying type, which isavailable in a ready-mix form. This process is also used to make repairsof defects, such as uneven surfaces, holes, depressions, gaps, dents,and other imperfections including those around electrical boxes, pipingand duct work, as well as corners created by the intersection of drywallboards.

It is well known in the art that finishing a joint between boards usinga joint tape typically involves three steps. First a thin layer of jointcompound is applied to the boards over the joint, and the tape isembedded into it. This step is commonly referred to as the embeddingstep. Next, a second coat of joint compound is applied over the embeddedjoint tape. This step is commonly referred to as the fill step. Thesecond coat of joint compound typically extends approximately two inchesbeyond the edges of the joint tape. Finally a third coat of jointcompound is applied over the first two coats, where the third coattypically extends even further out from the edges of the joint tape.This is commonly referred to as the finish step. Because paper jointtape will swell in the presence of the moisture from the joint compound,the second and third coats of joint compound cannot be applied until theprevious coat of joint compound and the joint tape are fully dry, whichoften takes as much as 24 hours. This means that as many as three daysare required to finish a board joint. Where the tape is a self-adhesivetape, only steps (ii) and (iii) are required, and therefore up to twofull days are needed to finish a joint.

Joint tape adds strength and crack resistance as well as smoothconcealment at flat joints and inside corners. Conventionally, threetypes of joint tape have been employed: a simple kraft paper strip; awoven glass fiber tape; and a non-woven glass fiber tape. Kraft paperstrips and non-woven glass fiber tape are adhered to the surfaces ofboard such as drywall by a bedding coat of joint compound or they areself-adhered. Woven glass fiber tape is typically of the self adhesivetype, but can also be fixed to the wall with staples. Once a paper jointtape has been applied, one must wait as much as a day for the jointcompound and tape to be fully dry before the next coat of joint compoundcan be applied.

Glass fiber tape is nonswellable and resists stretching and wrinkles.However nonwoven glass fiber tapes suffer from low tensile strength andare prone to cracking when used with conventional joint compounds. Wovenglass fiber tapes have sufficient tensile strength, but the board jointsproduced with drying-type joint compound are prone to cracking, and thuswoven glass fiber tapes are only recommended for use with setting typecompounds.

Accordingly, there remains a need in the art for an improved joint tapethat has high strength and reduced expansion due to moisture. Inaddition, there remains a need for an improved method of finishingjoints between pieces of board that reduces or eliminates the need towait until the joint compound has dried. The invention provides such ajoint tape and method. These and other advantages of the invention aswell as additional inventive features will be apparent from thedescription of the invention provided herein.

BRIEF SUMMARY OF THE INVENTION

The invention provides a joint tape for finishing a joint between boards(such as, for example, drywall, cement board, or the like) comprising anonwoven substrate that does not swell significantly in the presence ofwater and that has sufficient strength so as to resist tearing andcracking during application. In one embodiment, the joint tape comprisesa nonwoven substrate comprising fibers selected from the groupconsisting of natural pulp fibers, synthetic polymeric fibers, glassfibers, and combinations thereof, wherein the nonwoven substratepreferably has, as determined according to ASTM C474-05:

-   -   a crosswise percent expansion of less than about 1.3%;    -   a lengthwise percent expansion of less than about 0.2%; and    -   a tensile strength of at least about 15 pounds-force per inch in        the cross direction.

The invention further provides a method of finishing a joint betweenboards comprising the use of the joint tape of the invention. Applicantshave surprisingly discovered that using the joint tape of the invention,the time required to finish a joint can be substantially reduced. Inparticular, a second coat of joint compound can be applied over a firstcoat without having to wait for the first coat or the joint tape to dry.Accordingly, in another embodiment, the invention provides a methodcomprising (i) applying a joint tape of the invention to a joint betweenboards by embedding the tape in a first coat of joint compound, (ii)applying a second, fill coat of joint compound over the tape, andoptionally (iii) applying a third, fill or finish coat of joint compoundover the tape, wherein step ii and/or iii is carried out before theprevious coat and/or joint tape has substantially dried or set.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to joint tape, methods of finishing joints betweenboards, and reinforcements for cementitious materials generally.Finishing a board joint, as used herein, refers to applying tape andjoint compound to a joint between boards so as to create an assembly ofboards that, after finishing, can be further treated such as by applyingpaint, wallpaper, tile, paneling, and the like. The inventive joint tapecan be used with board used in forming walls, ceilings, floors,partitions, bathtub surround, vertical and horizontal shaft walls,stairwells, area separation walls, and the like. For example, the jointtape of the invention can be used with SHEETROCK® drywall products andDUROCK® cement board products, commercially available from United StatesGypsum Company as well as competing products, and the like. The boardmay be composed of any of a variety of materials, including but notlimited to, cementitious materials such as, for example, cement orgypsum. The term “drywall” is used illustratively, but as one ofordinary skill will appreciate, includes a variety of products such aswallboard, fiberboard, glass-faced gypsum boards, cement board, and thelike. The term “tape” means a strip of material that can be provided,for example, in roll form, which may or may not contain an adhesivebacking layer, and which desirably complies with the standards set forthin ASTM C474-05 and C475.

The invention is directed to a joint tape comprising a substratecomprising fibers that are substantially nonswellable in the presence ofmoisture. In this respect, the present invention is premised, at leastin part, on the inventors' surprising and unexpected discovery of ajoint tape comprising a substrate having a crosswise percent expansionof less than about 1.3% and a lengthwise percent expansion of less thanabout 0.2%, as determined according to ASTM C474-05. For example, insome embodiments, the substrate has a crosswise percent expansion ofless than about 1% and a lengthwise percent expansion of less than about0.15%. Preferably, the substrate has a crosswise percent expansion ofless than about 0.8% and a lengthwise percent expansion of less thanabout 0.1%. In some embodiments, the substrate has a crosswise percentexpansion of less than about 1.3% and a lengthwise percent expansion ofless than about 0.15%, a crosswise percent expansion of less than about1.3% and a lengthwise percent expansion of less than about 0.1%, acrosswise percent expansion of less than about 1% and a lengthwisepercent expansion of less than about 0.2%, a crosswise percent expansionof less than about 1% and a lengthwise percent expansion of less thanabout 0.1%, a crosswise percent expansion of less than about 0.8% and alengthwise percent expansion of less than about 0.2%, or a crosswisepercent expansion of less than about 1% and a lengthwise percentexpansion of less than about 0.15%.

It is also desirable that the joint tape have sufficient strength toavoid breaking during application to a drywall joint. Accordingly, thejoint tape of the invention preferably comprises a substrate having atensile strength of at least about 15 pounds-force per inch in the crossdirection, as determined according to ASTM C474-05. In some embodiments,the substrate has a tensile strength of at least about 18 pounds-forceper inch in the cross direction. Preferably the substrate has a tensilestrength of at least about 20 pounds-force per inch in the crossdirection.

The substrate is a nonwoven substrate. As used herein, the term“nonwoven substrate” refers to a web having a structure of individualfibers or threads which are interlaid, but not in an identifiable manneras in a knitted fabric. Nonwoven webs or fabrics have been formed frommany processes, such as, for example, meltblowing processes, spunbondingprocesses, and bonded carded web processes. The nonwoven substrate canhave any suitable pore size which provides for sufficient permeabilityof the joint compound through the tape to thereby enhancing the bond tojoint compound (i.e., at least about 90% bond to joint compound asdetermined in accordance with ASTM C 474-05) between the tape and thedrywall to which it is applied. Desirably the fluid permeability of thenonwoven substrate, measured as air resistance according to TAPPI T-460(Gurley method), is about 6 seconds or less (e.g., about 5 seconds orless, or about 4 seconds or less). The upper limit on the permeabilityof the nonwoven substrate is bound by the need for sufficient tensilestrength as discussed above.

The nonwoven substrate can comprise any suitable fibers. For example thenonwoven substrate can comprise fibers selected from the groupconsisting of natural pulp fibers, synthetic polymeric fibers, glassfibers, and combinations thereof. Natural pulp fibers can include woodpulp fibers including softwood and hardwood pulp fibers, straw fibers,plant and grass pulp fibers such as hemp, jute, kenaf, and bamboo pulpfibers, cotton pulp fibers, and the like. In some embodiments thenatural pulp fibers are wood pulp fibers, such as those used in papermaking. Synthetic polymeric fibers can include fibers comprisingpolymers selected from the group consisting of polyester, polyethylene,polypropylene, nylon, polyacetate, polyacrylic acid, polystyrene,polyvinyl acetate, rayon, polyvinylchloride, copolymers thereof andcombinations thereof. In some embodiments the synthetic polymeric fiberscomprise polyester, polyethylene, polypropylene, or a combinationthereof.

The fibers used to form the nonwoven substrate used in the inventivejoint tape are selected so as to satisfy the requirement for percentexpansion and tensile strength described above. Typically the nonwovensubstrate comprises a high percentage of synthetic polymeric fibers,preferably polyester fibers. In addition, the nonwoven substrate cancomprise natural pulp fibers, preferably wood pulp fibers, and/or glassfibers. In one embodiment, the nonwoven substrate comprises syntheticpolymeric fibers, wood pulp fibers, and glass fibers. In someembodiments, the nonwoven substrate comprises at least about 30 wt. % ormore synthetic polymeric fibers, less than about 1 wt. % natural pulpfibers, and/or less than about 50 wt. % glass fibers, wherein the weightis based on the total weight of the nonwoven substrate.

The nonwoven substrate used in the joint tape of the inventionoptionally further comprises a binder. Binders typically are addedduring formation of a nonwoven substrate to promote adherence of thefibers and to improve strength of the resulting substrate. The bindercan be any suitable binder, many of which are known in the art. Thebinder can be a polymer binder, for example a polymer formed from vinylacetate, vinyl alcohol, vinyl chloride, acrylic acid, ethyl vinylacetate, and ethyl vinyl chloride, starch, and combinations thereof.

The binder also can be a starch or starch derivative. Suitable starchesinclude corn, waxy corn, milo, white milo, wheat, potato and tapioca.Suitable starch derivatives include hydroxyethyl starch ether, starchacetate, starch phosphate, starch maleate, starch propionamide, cationicstarch, oxidized starch and cyanoethyl starch and in particular,hydroyethylated potato starch, cationic potato starch, acid modifiedcorn starch, hydroxyethylated corn starch, oxidized corn starch andmixtures thereof. Also included are cross-linked starches and starchconversion products, such as dextrins (e.g., white dextrins, canarydextrins and British gums), maltodextrins, thermochemically convertedstarches, and oxidized starches.

The binder preferably is selected from the group consisting of polyvinylalcohol, polyvinyl acetate, polyethylene vinyl acetate,polyvinylchloride, cross-linked starch, and combinations thereof. Insome embodiments, the binder desirably is a cross-linked starch. Inother embodiments, the binder desirably is polyvinyl alcohol and/orpolyvinyl acetate. In yet other embodiments, the binder desirably is amixture of a cross-linked starch and polyvinyl alcohol and/or polyvinylacetate.

The nonwoven substrate used in the inventive joint tape optionally iscoated at least in part with a bond enhancing agent. The bond enhancingagent is any agent that improves the bond between the joint tape and thejoint compound once the tape is applied to the wall and subsequentadhesion of the joint compound-permeated tape to the board (e.g.,drywall) surface. For example, the bond enhancing agent can be selectedfrom the group consisting of polymers formed from vinyl acetate, vinylalcohol, vinyl chloride, acrylic acid, ethyl vinyl acetate, and ethylvinyl chloride, starch, and combinations thereof. Preferably the bondenhancing agent is selected from the group consisting of polyvinylacetate, polyvinyl alcohol, and combinations thereof.

In some embodiments, the nonwoven substrate used in the inventive jointtape optionally comprises an adhesive on at least a back side of thenonwoven substrate. The adhesive can be used in place of, or in additionto, a bond enhancing agent. The adhesive typically is apressure-sensitive adhesive, many of which are known in the art. As usedherein, “pressure sensitive” refers to any releasable adhesive orreleasable tenacious means. Suitable adhesives include acrylateadhesives, e.g., isooctyl acrylate and acrylic acid copolymer, or vinylacetate-2 ethyl hexyl acrylate copolymer which can be combined withtackifiers. Alternatively, the adhesive may comprise the rapid settingthermoplastic “hot melt” adhesives.

In other embodiments it is desirable that the nonwoven substrate islightly sanded before application. Light sanding of the surface canimprove the bond of the tape to the joint compound during applicationand subsequent adhesion to the drywall surface. Sanding can be usedalone or in combination with a bond enhancing agent and/or adhesive.

The joint tape of the invention can have any suitable thickness.According to ASTM C474-05, joint tapes suitable for use in the industryshould have a thickness of about 0.012 inches or less. In someembodiments the joint tape of the invention has a thickness of about0.01 inches or less, or about 0.008 inches or less. Preferably the jointtape of the invention has a thickness of about 0.007 inches or less,about 0.006 inches or less, about 0.005 inches or less, or about 0.004inches or less.

The joint tape of any of the embodiments of the invention can furthercomprise any other suitable additives, such as dyes or pigments, flameretardants, and identification tags, many of which are known in the art.In addition, the joint tape can be pre-creased or scored through themiddle to facilitate application to interior angles.

The joint tape of the invention desirably is used to finish jointsbetween boards. One advantage of the joint tape of the invention is thatthe nonwoven substrate has low percent expansion in the presence ofmoisture. This feature is particularly desirable in the context offinishing joints between boards because application of the inventivejoint tape does not require one applying the tape to wait until thejoint compound and tape have dried before another coat of joint compoundcan be applied.

Accordingly, the joint tape in accordance with any embodiment of theinvention desirably is used in a method of finishing a drywall joint. Inone embodiment, the method comprises (i) embedding the joint tape in afirst coat of joint compound over the joint between boards, (ii)applying a second, fill coat of joint compound to the joint tape, andoptionally (iii) applying a third, fill or finish coat of joint compoundover the tape, wherein step (ii) and/or (iii) is carried out before theprevious coat has substantially dried. The method optionally furthercomprises (iv) applying a fourth fill or finish coat of joint compoundover the tape and, optionally, (v) applying a fifth finish coat of jointcompound over the tape, wherein steps (iv) and (v) are carried outbefore the preceding coat has substantially dried. The term “embed” asused herein means to set or place the tape at least partially onto orinto the joint compound. The joint tape can be fully or partiallyembedded in the joint compound.

In another embodiment, the method comprises (i) applying a joint tape inaccordance with any embodiments of the invention to a joint betweenboards using an adhesive such as a pressure sensitive adhesive, (ii)applying a first, fill coat of joint compound to the joint tape, andoptionally (iii) applying a second, fill or finish coat of jointcompound over the tape, wherein step (iii) is carried out before thefirst coat has substantially dried. The method optionally furthercomprises applying a third, fourth, or even fifth fill or finish coat ofjoint compound over the tape, wherein each additional coat is appliedbefore the previously applied coat has substantially dried.

The term “substantially dried” as used herein refers to the point atwhich the water present in a joint compound that has been applied over apaper joint tape has sufficiently evaporated such that any swelling ofthe tape that occurred due to the presence of the moisture hassubstantially or completely abated. In the inventive method, asubsequent coat of joint compound can be applied before any of the waterpresent in the joint compound has been removed, e.g., by evaporation.Typically a second or subsequent coat of joint compound can be appliedimmediately, such as within about 30 minutes, within about 1 hour, orwithin about 3 hours.

The following examples further illustrate the invention but, of course,should not be construed as in any way limiting its scope.

EXAMPLE

This example illustrate that nonswellable joint tapes in accordance withthe invention have tensile strengths and bonds to joint compound thatare comparable to conventional paper joint tapes.

A nonwoven material comprising a blend of polyester, glass, and woodpulp fibers (Ahlstrom 7136) was cut into two 3′ strips to mimic standardpaper joint tape dimensions. One strip was lightly sanded on one sideusing 120 grit sandpaper. The unsanded nonwoven strip had a thickness of9.5±0.3 mil (242±7 micron). The sanded nonwoven strip had a thickness of8.2±0.2 mil (207±4 micron).

In addition, two conventional paper joint tapes (Sheetrock™ brand tape)were obtained for comparative purposes. One of the paper joint tapes waslightly sanded on one side using 120 grit sandpaper. The unsanded paperstrip had a thickness of 8.5±0.3 mil (216±7 micron). The sanded paperstrip had a thickness of 8.5±0.1 mil (217±2 micron).

The tensile strength for each of the four strips was determined. Thetensile strength in the cross direction was determined following ASTM C474 (½″ gauge, 0.66 in/min, 73° F., 50% RH) for the sanded materials,and following TAPPI T 494om (7″ gauge, 1 in/min, 73° F., 50% RH) for theunsanded materials. The tensile strength in the machine direction wasdetermined following TAPPI T 494om (7″ gauge, 1 in/min, 73° F., 50% RH)for both the sanded and unsanded materials. The tensile strengths arereported in Table 1.

TABLE 1 Material Cross Direction Machine Direction Ahlstrom 7136 -unsanded 29.7 ± 0.7 lb/in 44.1 ± 1.1 lb/in (5200 ± 123 N/m) (7719 ± 192N/m) Ahlstrom 7136 - sanded 14.6 ± 1.3 lb/in 26.6 ± 3.5 lb/in (2564 ±119 N/m) (4651 ± 618 N/m) Paper - unsanded 30.1 ± 0.1 lb/in 52.7 ± 0.3lb/in (5274 ± 23 N/m) (9225 ± 50 N/m) Paper - sanded 31.1 ± 1.1 lb/in41.5 ± 1.5 lb/in (5441 ± 186 N/m) (7270 ± 270 N/m)

Each strip of nonwoven material was then applied to a wallboard(drywall) panel joint with SHEETROCK™ brand setting type joint compound.The resulting bond of the strip to the wallboard joint compound anddrywall surface was determined according to ASTM C474-05 under a varietyof conditions. The ASTM bond to joint compound for each material under avariety of conditions are provided in Table 2.

TABLE 2 Conditions Ahlstrom 7136 Paper Room temperature 100% 100% Oven(110° F.) 100% 100% 85° F./10% R.H. 100% 100% 75° F./50% R.H. 83%–100% 90%–100% 40° F./80% R.H. 0%–20% 56%–72% Recovery 75° F./50% R.H. 100%100%

These results demonstrate that nonwoven, nonswellable materials of theinvention can be used as joint tapes without sacrificing tensilestrength and bond to joint compound and drywall surface.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

1. A joint tape, comprising a nonwoven substrate comprising fibersselected from the group consisting of natural pulp fibers, syntheticpolymeric fibers, glass fibers, and combinations thereof, wherein thenonwoven substrate has as determined according to ASTM C474-05: acrosswise percent expansion of less than about 1.3% a lengthwise percentexpansion of less than about 0.2%; and a tensile strength of at leastabout 15 pounds-force per inch in the cross direction.
 2. The joint tapeof claim 1, wherein the nonwoven substrate has as determined accordingto ASTM C474-05: a crosswise percent expansion of less than about 0.8% alengthwise percent expansion of less than about 0.1%; and a tensilestrength of at least about 20 pounds-force per inch in the crossdirection.
 3. The joint tape of claim 1, wherein the fibers compriseboth natural pulp fibers and glass fibers.
 4. The joint tape of claim 1,wherein the fibers comprise synthetic polymeric fibers selected from thegroup consisting of polyester, polyethylene, polypropylene, nylon,polyacetate, polyacrylic, polystyrene, polyvinyl acetate, rayon,polyvinylchloride, copolymers thereof and combinations thereof.
 5. Thejoint tape of claim 1, wherein the fibers comprise polyester fibers. 6.The joint tape of claim 1, wherein the fibers comprise natural pulpfibers and the natural pulp fibers are wood pulp fibers.
 7. The jointtape of claim 1, wherein the nonwoven substrate comprises a binder. 8.The joint tape of claim 7, wherein the binder is selected from the groupconsisting of polyvinyl alcohol, polyvinyl acetate, polyethylene vinylacetate, polyvinylchloride, starch, cross-linked starch, andcombinations thereof.
 9. The joint tape of claim 7, wherein the binderis cross-linked starch or a combination of cross-linked starch andpolyvinyl alcohol.
 10. The joint tape of claim 1, wherein the nonwovensubstrate is coated at least in part with a bond enhancing agent. 11.The joint tape of claim 10, wherein the bond enhancing agent is selectedfrom the group consisting of polymers formed from vinyl acetate, vinylalcohol, vinyl chloride, acrylic acid, ethyl vinyl acetate, and ethylvinyl chloride, starch, and combinations thereof.
 12. The joint tape ofclaim 10, wherein the bond enhancing agent is polyvinyl acetate,polyvinyl alcohol, or a combination thereof.
 13. The joint tape of claim1, further comprising an adhesive on at least a back side of thenonwoven substrate.
 14. The joint tape of claim 1, wherein the nonwovensubstrate comprises at least about 30 wt. % or more synthetic polymericfibers based on the total weight of the nonwoven substrate.
 15. Thejoint tape of claim 1, wherein the nonwoven substrate comprises lessthan about 1 wt. % natural pulp fibers.
 16. A method of finishing ajoint between boards, comprising: (i) applying a joint tape comprising anonwoven substrate comprising fibers selected from the group consistingof natural pulp fibers, synthetic polymeric fibers, glass fibers, andcombinations thereof to the joint between boards by at least partiallyembedding the joint tape in a first coat of joint compound, wherein thenonwoven substrate has as determined according to ASTM C474-05 acrosswise percent expansion of less than about 1.3%, a lengthwisepercent expansion of less than about 0.2%; and a tensile strength of atleast about 15 pounds-force per inch in the cross direction; and (ii)applying a second coat of joint compound over the tape, wherein step(ii) is carried out before the first coat of joint compound applied in(i) has substantially dried.
 17. The method of claim 16, wherein thenonwoven substrate further comprises an adhesive on at least a back sideof the nonwoven substrate.
 18. The method of claim 16, furthercomprising (iii) applying a third coat of joint compound over the tape,wherein step (iii) is carried out before the second coat hassubstantially dried.
 19. The method of claim 16, wherein the boards areselected from the group consisting of drywall boards and cement boards.20. A method of finishing a joint between boards, comprising: (i)applying a joint tape comprising a nonwoven substrate comprising fibersselected from the group consisting of natural pulp fibers, syntheticpolymeric fibers, glass fibers, and combinations thereof, and anadhesive on at least a back side of the nonwoven substrate, to the jointbetween boards using the adhesive, wherein the nonwoven substrate has asdetermined according to ASTM C474-05 a crosswise percent expansion ofless than about 1.3%, a lengthwise percent expansion of less than about0.2%; and a tensile strength of at least about 15 pounds-force per inchin the cross direction; and (ii) applying a first coat of joint compoundover the tape, and (iii) applying a second coat of joint compound overthe tape, wherein step (iii) is carried out before the first coat ofjoint compound applied in (ii) has substantially dried.